This invention relates to a device for grasping and transferring the labels from a store to an applicator drum, in the labelling machines having a stationary store for the labels and intended to label bottles and the like.
In the conventional labelling machines, the label store was made to oscillate in synchronism with the rotation of an applicator drum so as to transfer onto said drum, one by one, the labels contained in the store. However, the need for oscillating the label store, which has a heavy mass, hindered the attainment of high labelling speeds. To improve this situation, devices have been proposed for transferring the labels, one by one, from a stationary store to the applicator drum, by means of a number of vanes peripherically mounted on a rotating plate and controlled by means of cams so as to give rise to a complicated movement, comprising lapping on a glueing roller, abutting against the first label of the store and then transferring said label to the applicator drum. However, even with the known devices of this type limitations to the operation speed are encountered, because of the forces of inertia due to the complexity of the vanes movement, and also because the vanes are mounted peripherically on the rotating plate and therefore they follow a large radius trajectory and are subjected to a high centrifugal force which, beginning from a certain speed, results in detachment of the conveyed labels. Even within the available speed limits, these devices give rise to vibrations and noise and have a reduced life owing to the overloads which are applied to the components.